Stories of ‘deadly’ plants wrecking people’s lives

Poison garden tour.

Tom Pattinson, Gardening Correspondent

Published:00:32Friday 08 August 2014

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I’ve always had an interest in the diverse properties of plants, economic, social, medicinal or poisonous, but the one aspect that fascinates most, really took off when the Poison Garden at Alnwick opened.

Here was an opportunity to become involved and convey to the general public just how dark and sinister an innocent-looking plant can be. The short, controlled tours, with small groups, are taken by trained guides who use real-life examples of deadly plants wrecking people’s lives.

Deadly ricin plant.

It’s not just the notorious Cannabis sativa, growing there under licence from The Home Office, hemlock, the infamous poison that ended Socrates’ life, Atropa belladonna (deadly nightshade) or ultra-poisonous ricinis you need to watch, visitors are shocked to discover that plants they grow in their own gardens are potential killers too.

For example, monkshood (aconitum) and columbine (aquilegia) both contain the deadly alkaloid aconitine.

Foxglove (digitalis) introduces itself to most cultivated sites via self-seeding, and the sight of bumblebees entering the flowers is captivating but the plant contains a glycocide that kills.

Adults are unlikely to go around nibbling at ornamental plant parts but children of a certain age do it without thought. All the more reason to discover a little more about the species you cultivate if you have toddlers playing in the garden.

Alkaloids are the most common plant poisons and 10 per cent of all species contain them. Several thousand different types have been identified and they all have an adverse pharmacological effect on animals. Some species contain several alkaloids making them even more dangerous when ingested.

Echium, fritillaria, laburnum and box fall into this category.

Cardiac glycocides, as the name suggests, have the ability to affect the heart. Lily of the valley, foxglove, oleander and daphne contain them.

Why not pay a visit to the Poison Garden in Alnwick and see if you recognise any of the 80-plus plants growing there.

Hear what effect the different toxic chemicals can have on the body and develop a healthier respect for plants you perhaps already grow.

** There was a news item on local television recently relating to the discovery of a corn-cockle (Agrostemma githago) plant growing near a tourist attraction along the coast.

Excitement surrounded the find because the plant was thought to be extinct in the wild, although seed can be bought online or in wild flower mixtures. This was tempered by a reference to its poisonous properties.

With children on the long summer break, some of which will be spent in the garden and countryside, I’d say this was a timely reminder that many of the plants we take so much for granted simply cannot be trusted.

Now rarely seen, corn-cockle was once abundant in fields of grain and added a distinctly bitter taste to the resultant bread.

But a combination of modern herbicides and processes to produce cleaner grain seed led to its downfall and believed extinction.

The plant is easily identified at the point of flowering as the purple petals are folded together like a flag before unfurling. Its slight resemblance to a campion flower is because they both belong to the family caryophyllaceae.

All parts of the corn-cockle are poisonous. They contain the glycocide githagin and agrostemmic acid. The effect of ingestion can range from severe stomach pains to sickness, breathing difficulty or death depending on the amount consumed.

But corn-cockle is not a lone offender, many countryside plants have poisonous properties.

All the more reason to leave well alone, and if you do touch them, at least wash your hands before eating, as you would after a gardening session.

** Poisonous plants aside, there are several other ways seemingly harmless garden subjects can cause distress.

Most dangerous are plants that cause a sensitivity to light (photosensitisers) on contact with the skin.

These include citrus plants, angelica, hypericum, rue and giant hogweed. The last two mentioned can cause severe blisters and possible liver damage in severe cases.

Allergenic plants abound. It can be the sap, pollen grains, leaves; from achillea to tagetes, the list is long.

Mechanical injury is common too. It can be the rough hairs on comfrey or fine hairs on mullein, that cause us to rub and scratch incessantly.

Last week I was caught out by the oldest plant injury type of all – mechanical and chemical. It occurred when I grasped a handful of grass by the riverside and discovered there were nettles in it. Worse still, there was not a dock leaf in sight!